<!DOCTYPE html>
<html lang="" style="height: 100%;">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">

</head>
<body style="height: 100%;">

<script>

    function test() {
        console.log('this is test ------------------------------')
        let i
        if( true){
            i = 55
        }
        console.log('this is i ------------------------------'+i)
    }
    test()
</script>
</body>
</html>
